无涯教程-ASP.NET MVC - 脚手架

无涯教程
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ASP.NET Scaffolding是ASP.NET Web应用程序的代码生成框架， Visual Studio 2013包括针对MVC和Web API项目的预安装代码生成器，当您要快速添加与数据模型交互的代码时，可以将脚手架添加到项目中，使用脚手架可以减少在项目中开发标准数据操作的时间。

让我们看一个简单的示例。我们将创建包含模型类Employee的相同示例，但是这次我们将使用脚手架。

步骤1 -打开Visual Studio，然后单击File→New→Item菜单选项。

将打开一个"New Project"对话框。

New Dialog

步骤2 - 在左侧窗格中，选择Template→Visual C#→Web。

步骤3 - 在中间窗格中，选择ASP.NET Web应用程序。

步骤4 - 在"Name"字段中输入项目名称" MVCScaffoldingDemo"，然后单击"OK"继续。您将看到以下对话框，要求您设置ASP.NET项目的初始内容。

MVCScaffoldingDemo

步骤5 - 为简单起见，请选择"Empty"选项，然后在"Add folders and core references for"部分中选中" MVC"复选框，然后单击"OK"。

它将创建具有最少预定义内容的基本MVC项目。

通过Visual Studio创建项目后，您将在"Solution Explorer"窗口中看到许多文件和文件夹。

Project Created by Visual Studio

添加Entity framework

第一步是安装Entity framework。右键单击项目，然后选择NuGet Package Manager→Manage NuGet Packages for Solution…

NuGet Package Manager

它将打开" NuGet Package Manager"。在搜索框中搜索Entity framework。

Entity Framework Search Box

选择Entity framework，然后单击"Install"按钮。它将打开"Preview"对话框。

Open Preview Dialog

单击确定继续。

Click Ok to Continue

点击"I Accept"按钮开始安装。

I Accept Button Installation

一旦安装了Entity framework，您将在输出窗口中看到该消息，如上面的屏幕快照所示。

新增模型

要添加模型，请在Solution Explorer中的Models文件夹上单击鼠标右键，然后选择Add→Class。您会看到"Add New Item"对话框。

Item Dialog

在中间窗格中选择"Class"，然后在名称字段中输入Employee.cs。

使用以下代码向Employee类添加一些属性。

using System;

namespace MVCScaffoldingDemo.Models {
public class Employee{
public int ID { get; set; }
public string Name { get; set; }
public DateTime JoiningDate { get; set; }
public int Age { get; set; }
}
}

添加DBContext

我们有一个Employee Model，现在我们需要添加另一个类，该类将与Entity Framework通信以检索和保存数据，以下是Employee.cs文件中的完整代码。

using System;
using System.Data.Entity;

namespace MVCScaffoldingDemo.Models{
public class Employee{
public int ID { get; set; }
public string Name { get; set; }
public DateTime JoiningDate { get; set; }
public int Age { get; set; }
}


public class EmpDBContext : DbContext{
public DbSet<Employee> Employees { get; set; }
}
}

如您所见，" EmpDBContext"是从称为" DbContext"的EF类派生的，在此类中，我们有一个名为DbSet的属性，该属性基本上表示您要查询和保存的实体。

现在，我们来构建解决方案，成功构建项目后，您会看到一条消息。

Project Successfully Build

添加脚手架

要Add Scaffold，请在Solution Explorer中的Controllers文件夹上单击鼠标右键，然后选择"Add"→"New Scaffolded Item"。

New Scaffolded Item

它将显示"Add Scaffold"对话框。

Display Scaffold Dialog

使用中间窗格中的Entity Framework选择带有视图的MVC 5 Controller，然后单击"Add"按钮，这将显示"Add Controller"对话框。

Entity Framework Middle Pane

从"Moel"类下拉列表中选择"Employees"，从DBcontext类下拉列表中选择EmpDBContext。您还将看到默认情况下已选择控制器名称。

单击"Add"按钮继续，您将在EmployeesController中看到以下代码，该代码是由Visual Studio使用脚手架创建的。

using System.Data.Entity;
using System.Linq;
using System.Net;
using System.Web.Mvc;
using MVCScaffoldingDemo.Models;

namespace MVCScaffoldingDemo.Controllers {
public class EmployeesController : Controller{
private EmpDBContext db = new EmpDBContext();


  </span><span class="com">//GET: Employees</span><span class="pln">
  </span><span class="kwd">public</span><span class="pln"> </span><span class="typ">ActionResult</span><span class="pln"> </span><span class="typ">Index</span><span class="pun">(){</span><span class="pln">
     </span><span class="kwd">return</span><span class="pln"> </span><span class="typ">View</span><span class="pun">(</span><span class="pln">db</span><span class="pun">.</span><span class="typ">Employees</span><span class="pun">.</span><span class="typ">ToList</span><span class="pun">());</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">
  
  </span><span class="com">//GET: Employees/Details/5</span><span class="pln">
  </span><span class="kwd">public</span><span class="pln"> </span><span class="typ">ActionResult</span><span class="pln"> </span><span class="typ">Details</span><span class="pun">(</span><span class="kwd">int</span><span class="pun">?</span><span class="pln"> id</span><span class="pun">){</span><span class="pln">
     </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">id </span><span class="pun">==</span><span class="pln"> </span><span class="kwd">null</span><span class="pun">){</span><span class="pln">
        </span><span class="kwd">return</span><span class="pln"> </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">HttpStatusCodeResult</span><span class="pun">(</span><span class="typ">HttpStatusCode</span><span class="pun">.</span><span class="typ">BadRequest</span><span class="pun">);</span><span class="pln">
     </span><span class="pun">}</span><span class="pln">
		
     </span><span class="typ">Employee</span><span class="pln"> employee </span><span class="pun">=</span><span class="pln"> db</span><span class="pun">.</span><span class="typ">Employees</span><span class="pun">.</span><span class="typ">Find</span><span class="pun">(</span><span class="pln">id</span><span class="pun">);</span><span class="pln">
		
     </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">employee </span><span class="pun">==</span><span class="pln"> </span><span class="kwd">null</span><span class="pun">){</span><span class="pln">
        </span><span class="kwd">return</span><span class="pln"> </span><span class="typ">HttpNotFound</span><span class="pun">();</span><span class="pln">
     </span><span class="pun">}</span><span class="pln">
     </span><span class="kwd">return</span><span class="pln"> </span><span class="typ">View</span><span class="pun">(</span><span class="pln">employee</span><span class="pun">);</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">
  
  </span><span class="com">//GET: Employees/Create</span><span class="pln">
  </span><span class="kwd">public</span><span class="pln"> </span><span class="typ">ActionResult</span><span class="pln"> </span><span class="typ">Create</span><span class="pun">(){</span><span class="pln">
     </span><span class="kwd">return</span><span class="pln"> </span><span class="typ">View</span><span class="pun">();</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">
  
  </span><span class="com">//POST: Employees/Create</span><span class="pln">
  </span><span class="com">//To protect from overposting attacks, please enable the specific</span><span class="pln">
  properties you want to bind to</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">for</span><span class="pln">
  </span><span class="com">//more details see http://go.microsoft.com/fwlink/?LinkId=317598.</span><span class="pln">
  </span><span class="pun">[</span><span class="typ">HttpPost</span><span class="pun">]</span><span class="pln">
  </span><span class="pun">[</span><span class="typ">ValidateAntiForgeryToken</span><span class="pun">]</span><span class="pln">
	
  </span><span class="kwd">public</span><span class="pln"> </span><span class="typ">ActionResult</span><span class="pln"> </span><span class="typ">Create</span><span class="pun">([</span><span class="typ">Bind</span><span class="pun">(</span><span class="typ">Include</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> </span><span class="str">"ID,Name,JoiningDate,Age"</span><span class="pun">)]</span><span class="pln">
  </span><span class="typ">Employee</span><span class="pln"> employee</span><span class="pun">){</span><span class="pln">
     </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="typ">ModelState</span><span class="pun">.</span><span class="typ">IsValid</span><span class="pun">){</span><span class="pln">
        db</span><span class="pun">.</span><span class="typ">Employees</span><span class="pun">.</span><span class="typ">Add</span><span class="pun">(</span><span class="pln">employee</span><span class="pun">);</span><span class="pln">
        db</span><span class="pun">.</span><span class="typ">SaveChanges</span><span class="pun">();</span><span class="pln">
        </span><span class="kwd">return</span><span class="pln"> </span><span class="typ">RedirectToAction</span><span class="pun">(</span><span class="str">"Index"</span><span class="pun">);</span><span class="pln">
     </span><span class="pun">}</span><span class="pln">
     </span><span class="kwd">return</span><span class="pln"> </span><span class="typ">View</span><span class="pun">(</span><span class="pln">employee</span><span class="pun">);</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">
  
  </span><span class="com">//GET: Employees/Edit/5</span><span class="pln">
  </span><span class="kwd">public</span><span class="pln"> </span><span class="typ">ActionResult</span><span class="pln"> </span><span class="typ">Edit</span><span class="pun">(</span><span class="kwd">int</span><span class="pun">?</span><span class="pln"> id</span><span class="pun">){</span><span class="pln">
     </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">id </span><span class="pun">==</span><span class="pln"> </span><span class="kwd">null</span><span class="pun">){</span><span class="pln">
        </span><span class="kwd">return</span><span class="pln"> </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">HttpStatusCodeResult</span><span class="pun">(</span><span class="typ">HttpStatusCode</span><span class="pun">.</span><span class="typ">BadRequest</span><span class="pun">);</span><span class="pln">
     </span><span class="pun">}</span><span class="pln">
		
     </span><span class="typ">Employee</span><span class="pln"> employee </span><span class="pun">=</span><span class="pln"> db</span><span class="pun">.</span><span class="typ">Employees</span><span class="pun">.</span><span class="typ">Find</span><span class="pun">(</span><span class="pln">id</span><span class="pun">);</span><span class="pln">
		
     </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">employee </span><span class="pun">==</span><span class="pln"> </span><span class="kwd">null</span><span class="pun">){</span><span class="pln">
        </span><span class="kwd">return</span><span class="pln"> </span><span class="typ">HttpNotFound</span><span class="pun">();</span><span class="pln">
     </span><span class="pun">}</span><span class="pln">
     </span><span class="kwd">return</span><span class="pln"> </span><span class="typ">View</span><span class="pun">(</span><span class="pln">employee</span><span class="pun">);</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">
  
  </span><span class="com">//POST: Employees/Edit/5</span><span class="pln">
  </span><span class="com">//To protect from overposting attacks, please enable the specific</span><span class="pln">
  properties you want to bind to</span><span class="pun">,</span><span class="pln"> </span><span class="kwd">for</span><span class="pln">
  </span><span class="com">//more details see http://go.microsoft.com/fwlink/?LinkId=317598.</span><span class="pln">
  </span><span class="pun">[</span><span class="typ">HttpPost</span><span class="pun">]</span><span class="pln">
  </span><span class="pun">[</span><span class="typ">ValidateAntiForgeryToken</span><span class="pun">]</span><span class="pln">
  </span><span class="kwd">public</span><span class="pln"> </span><span class="typ">ActionResult</span><span class="pln"> </span><span class="typ">Edit</span><span class="pun">([</span><span class="typ">Bind</span><span class="pun">(</span><span class="typ">Include</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> </span><span class="str">"ID,Name,JoiningDate,Age"</span><span class="pun">)]</span><span class="typ">Employee</span><span class="pln"> employee</span><span class="pun">){</span><span class="pln">
     </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="typ">ModelState</span><span class="pun">.</span><span class="typ">IsValid</span><span class="pun">){</span><span class="pln">
        db</span><span class="pun">.</span><span class="typ">Entry</span><span class="pun">(</span><span class="pln">employee</span><span class="pun">).</span><span class="typ">State</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> </span><span class="typ">EntityState</span><span class="pun">.</span><span class="typ">Modified</span><span class="pun">;</span><span class="pln">
        db</span><span class="pun">.</span><span class="typ">SaveChanges</span><span class="pun">();</span><span class="pln">
        </span><span class="kwd">return</span><span class="pln"> </span><span class="typ">RedirectToAction</span><span class="pun">(</span><span class="str">"Index"</span><span class="pun">);</span><span class="pln">
     </span><span class="pun">}</span><span class="pln">
     </span><span class="kwd">return</span><span class="pln"> </span><span class="typ">View</span><span class="pun">(</span><span class="pln">employee</span><span class="pun">);</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">
  
  </span><span class="com">//GET: Employees/Delete/5</span><span class="pln">
  </span><span class="kwd">public</span><span class="pln"> </span><span class="typ">ActionResult</span><span class="pln"> </span><span class="typ">Delete</span><span class="pun">(</span><span class="kwd">int</span><span class="pun">?</span><span class="pln"> id</span><span class="pun">){</span><span class="pln">
     </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">id </span><span class="pun">==</span><span class="pln"> </span><span class="kwd">null</span><span class="pun">){</span><span class="pln">
        </span><span class="kwd">return</span><span class="pln"> </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">HttpStatusCodeResult</span><span class="pun">(</span><span class="typ">HttpStatusCode</span><span class="pun">.</span><span class="typ">BadRequest</span><span class="pun">);</span><span class="pln">
     </span><span class="pun">}</span><span class="pln">
		
     </span><span class="typ">Employee</span><span class="pln"> employee </span><span class="pun">=</span><span class="pln"> db</span><span class="pun">.</span><span class="typ">Employees</span><span class="pun">.</span><span class="typ">Find</span><span class="pun">(</span><span class="pln">id</span><span class="pun">);</span><span class="pln">
		
     </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">employee </span><span class="pun">==</span><span class="pln"> </span><span class="kwd">null</span><span class="pun">){</span><span class="pln">
        </span><span class="kwd">return</span><span class="pln"> </span><span class="typ">HttpNotFound</span><span class="pun">();</span><span class="pln">
     </span><span class="pun">}</span><span class="pln">
     </span><span class="kwd">return</span><span class="pln"> </span><span class="typ">View</span><span class="pun">(</span><span class="pln">employee</span><span class="pun">);</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">
  
  </span><span class="com">//POST: Employees/Delete/5</span><span class="pln">
  </span><span class="pun">[</span><span class="typ">HttpPost</span><span class="pun">,</span><span class="pln"> </span><span class="typ">ActionName</span><span class="pun">(</span><span class="str">"Delete"</span><span class="pun">)]</span><span class="pln">
  </span><span class="pun">[</span><span class="typ">ValidateAntiForgeryToken</span><span class="pun">]</span><span class="pln">
	
  </span><span class="kwd">public</span><span class="pln"> </span><span class="typ">ActionResult</span><span class="pln"> </span><span class="typ">DeleteConfirmed</span><span class="pun">(</span><span class="kwd">int</span><span class="pln"> id</span><span class="pun">){</span><span class="pln">
     </span><span class="typ">Employee</span><span class="pln"> employee </span><span class="pun">=</span><span class="pln"> db</span><span class="pun">.</span><span class="typ">Employees</span><span class="pun">.</span><span class="typ">Find</span><span class="pun">(</span><span class="pln">id</span><span class="pun">);</span><span class="pln">
     db</span><span class="pun">.</span><span class="typ">Employees</span><span class="pun">.</span><span class="typ">Remove</span><span class="pun">(</span><span class="pln">employee</span><span class="pun">);</span><span class="pln">
     db</span><span class="pun">.</span><span class="typ">SaveChanges</span><span class="pun">();</span><span class="pln">
     </span><span class="kwd">return</span><span class="pln"> </span><span class="typ">RedirectToAction</span><span class="pun">(</span><span class="str">"Index"</span><span class="pun">);</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">
  
  </span><span class="kwd">protected</span><span class="pln"> </span><span class="kwd">override</span><span class="pln"> </span><span class="kwd">void</span><span class="pln"> </span><span class="typ">Dispose</span><span class="pun">(</span><span class="kwd">bool</span><span class="pln"> disposing</span><span class="pun">){</span><span class="pln">
     </span><span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">disposing</span><span class="pun">){</span><span class="pln">
        db</span><span class="pun">.</span><span class="typ">Dispose</span><span class="pun">();</span><span class="pln">
     </span><span class="pun">}</span><span class="pln">
		
     </span><span class="kwd">base</span><span class="pun">.</span><span class="typ">Dispose</span><span class="pun">(</span><span class="pln">disposing</span><span class="pun">);</span><span class="pln">
  </span><span class="pun">}</span><span class="pln">



}
}

运行您的应用程序，并指定以下URL http://localhost:59359/employees 。您将看到以下输出。

Run Your Application

您可以看到View中没有数据，因为我们没有向Visual Studio创建的数据库添加任何记录。

通过点击"Create New"链接从浏览器中添加一条记录，它将显示"Create"视图。

Clicking Create New

让我们在以下字段中添加一些数据。

Adding Data in Field

点击"Create"按钮，它将更新索引视图。

Update Index View

您可以看到新记录也已添加到数据库中。

New Record Added

如您所见，我们通过使用Scaffolding实现了相同的示例，这是从模型类创建Views和Action方法的简便得多的方法。

参考链接

www.learnfk.com/asp.net_mvc…

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